Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Dus10R

Contributing Members
  • Posts

    210
  • Joined

  • Last visited

Posts posted by Dus10R

  1. Another thought... Have you removed and cleaned the throttle body? They can gunk up sometimes and will cause the car to run poorly and die at idle. Also try a throttle body reset.

    Turn the ignition key on but dont start the car, let it sit for about a minute, if you stand at the back of the car you should hear a high pitched whine and a few clicks as the throttle body resets itself. When its done and no longer making any noises, dont turn the key off but do start it and let it idle for 10 minutes or so...

    Changing the battery could have somehow got the throttle body out of whack.

  2. Best case scenario, plug or plugs are fouled, you said you changed coil pack, did you check the plug?

    If the plug is good and the coil pack is too, then it could be fuel pump, or even an injector. You know its not burning the fuel because your MPG has gone to crap, which could mean a stuck open injector thats flooding the cylinder and fouling the plug.

    Just for grins, check your ground strap too, its a known problem on these cars and Porsche sells an improved part to fix it.

    Worse case scenario is the DME is fried somehow but if your getting codes and none are DME related then thats probably not the case.

    (just running thru in my head and typing as it comes to me...haha)

    Rough idle, can be vacuum leaks too, look around in your engine compartment for any broke vacuum lines.

  3. 82k miles, water pump at 79k miles, original clutch, no smoke on start, burns almost no oil. Daily driver. Has developed some sort of random transmission fluid leak, doesn't do it all the time, only if I drive it hard for about an hour, shop cant find it, nobody has any idea what can be leaking, randomly. Has developed some sort of rattle at the back, I think its exhaust related, maybe a heat shield or something, cant pinpoint the sound. The CV joints at the front are starting to bind a bit when I crank the wheel hard to one side while backing up, may be normal, but my last Porsche didn't do this so I dont know. Suspension may need a refresh soon, sounds overly harsh when I drive over bumps or small pot holes, but still handles perfectly. Have a really hard time getting into first gear unless car is completly stopped, and second gear is a pain when its cold. All little annoyances, but nothing I cant live with. Car has been good, and will hopefully last till my next upgrade in a few years (Good Lord willing).

  4. X51 cars have different camshafts and valvetrains too, so without that your dollar to horsepower advantage may be very low. As you have a bottle neck. Also, these 3.8 motors have design weaknesses in cooling, hence why the X51 needs the extra radiator, its because when they bored the 3.6 engine out to the 3.8 the coolant passages got smaller. And Porsche went cheap and went from left and right dependent head gaskets with coolant holes sized differently to control the amount of coolant that each cylinder received, to a generic head gasket that fits both sides, with coolant holes all the same size. Add that to the bad design of putting the oil squirters on the bottom of the pistons instead of the top where gravity can work to cover the whole piston, and you get a motor with some serious weak points. Increasing the horsepower just exacerbates the problem. Make sure and change out your thermostat to a cooler unit too. You want to keep these motors as cool as possible, and I would maybe even add an additional oil cooler too if you're going to increase the power. If your motor has over 25,000 miles on it, Porsche says that the Crankshaft Main Bearing and the connecting rod bearings MUST be replaced, and the cylinders need to be inspected for the above mentioned cylinder scaring and connecting rod Bushings scaring before installing the X51. I think too that the MAF plugs are different, and the DME plugs are different, and the DME has to be completely reprogrammed, Porsche even goes so far as to give it a new part number when they're done. Its a bold undertaking for sure. Good luck!

  5. Didnt some of the early cars have problems with the grounding cable? I think it was even a recall or a TSB. Could that be it? Have the battery checked too, these cars don't like weak batteries.

    Water pump, is very very common for the mileage.

    I went from a bomb proof 996 Turbo, to a 997 Carrera S. Then afterward came across a 60 page report about all of the design weaknesses these motors have. I came close to selling the car the very next day, it made me so paranoid.

    But I did not. I added the Porsche 3rd radiator kit (Porsche kit, sold by Suncoast for really reasonable) and added aTungsten Disulphide oil additive, changed the thermostat out to a cooler unit that starts circulating coolant sooner than the stock unit. And I drive it almost daily. Now has 82k miles and no smoke on start-up, burns very little to no oil.

    So I say this to give you a small heads up that there can be some major problems with these engines, but if treated right, and you stay observant to some things and service the car more than Porsche recommends, it should be fairly problem free.

    I've noticed in the past on two Porsche's that I bought that didnt have a lot of miles and hadnt been driven a lot, that when I started driving them daily I had a few quirks develop soon afterwards. Fixed those quirks and the cars remained fairly trouble free.

    I honestly think the more you drive them the more reliable they are. Letting them sit, and then driving them every once in awhile I think leads to little quirks and problems.

    Send me an email if you want the report...it may scare you, but its good info. to be aware of, so you can recognize any of the major problems if they start to develop. Dustinr@nvbell.net

  6. Water pump usually goes from 50k miles to 70k miles, crawl up underneath and look for weeps and see if you can feel any slop in the pulley. If you have stock exhaust its usually not too bad to replace. The water pump is easy to find, if you dont already know, if you're looking at the back of the car its on the driver side, on the bottom, at the rear of the motor, its the lowest, farthest left, pulley.

    Theres some pretty good DIY's on the web. Order the part from Suncoast, they're the cheapest by far, and while you're at, if it hasn't been done before, might as well change out the serp. Belt too.

    The water pump itself is nothing more than a small aluminum cover with a pulley on one side, and a plastic impeller on the other, i bet its no more than 4 or 5 inches thick. The problem is the engine cradle is so close to the back of the motor that there isnt enough room to pull the WP out and then drop it down. I have a full AWE exhaust, and if it wasn't for that, I could of probably had it out and reinstalled in an hour or two. But with the AWE, the whole exhaust system had to be removed so that the bracket would move enough out of the way to get the pump out. I was so frustrated as I was only lacking about 32nds of an inch to get the pump out with the exhaust still installed. Murphy's Law...

    But its not a hard job, just takes some time and small carny hands, haha.

  7. We'll know how good the 9A1 motor is when the new GT3 comes out. If the GT3 uses the same motor then its probably a good engine. If it uses a different engine with a true dry sump like all of its predecessors than its up in the air still whether or not the 9A1 is good.

    Whatever motor the GT3 versions use, are usually the best engines. Its sad, but since the 996, Porsche has created two types of 911's, what I call the: Dumbed-down, Cost-over-Quality version, normal 911 & then the Money-no-Object, Quality-over-Cost version, GT3 (and Turbo (up to 2011).

    Example? New 997 M97 motor cost $18k to $20k. New 9A1 motor costs $22k to $25k

    GT3 motor cost: $50k to $63k

    Think there is some quality differences between the three?

  8. Have you scanned it for codes to make sure the ECU is still working?

    Also check to see if the throttle body (TB) is operating, turn the key on and let it sit, go back by the engine bay and you should hear a whine and a few ticks as the throttle body runs through a cycle and does a reset, usually takes a minute for it to start after you turn the key on. If you dont hear this, the TB may be bad and could be fully closed not allowing enough air in for the car to start.

    You did fuel pump, did you change the fuel filter?

    Plus the clutch switch as mentioned already.

  9. Are you replacing the key head you have now or is this an addition?

    If its a replacement, you can remove the internal rfid chip from your old key head and insert it into the new key head and that will take care of the ignition, then I think you just need to have the car programmed to the key so that it will recognize its freq. an remotely unlock the doors. The RFID chip is a little glass bead which can be removed and replaced.

    Its been five years since I had it done, but I think thats what I remember doing.

  10. Just a question: have you researched the PCCB's? Their only advantage is weight. They weigh half as much as the normal rotors...BUT and it's a big one, they don't last long at all if driven hard, they WILL NOT last the life of the car like Porsche used to claim, if you track the car often. AND... they don't have the feel from cold that the stock rotors do. Carbon rotors don't start to feel good until they're very hot, up till that point they feel kind of vague.

    Now switching over to the 6 piston caliper and a 997 Turbo rotor (or Girodisc) is a worthy upgrade and if weight is a concern, trying dropping it via lighter 18" wheels. Don't go 19"... yes they fit, but the weight penalty is big and the car will not handle as well despite the forum posts that you read. Porsche had to redesign a lot of suspension components to make the 997's work well with 19" wheels, the 996 was not designed for 19" wheels. (off topic sorry)

    But if you you just drive on the street, the PCCB's will last a long time, they just don't feel as good.

  11. I think the common denominator is aftermarket exhaust... I bought a Carrera S with full AWE exhaust system and mine does it too. Pretty bad sometimes... From 1500- 2000 rpm and it feels like a turbo with bad spark plugs. Its heart skips a beat and then she's good to go. I drive around it, but it sucks that I have to. And if someone else drives it I have to tell them not to juice it from way down low or if they do then I have to explain that its normal...lame. I need to run some Durametric logs and see what actually happens...check AFR's, Throttle, Cam Position, etc...

    But this post is old, anyone able to figure this one out in the past two years?

  12. 2nd thought...when you cleaned the TB did you remove it from the car or just clean it while connected?

    The best way is to remove it entirely, its easy...one connector and 4 bolts.

    You can manually push the throttle plate open with your finger and you should feel some tension and then it should close itself, but not all the way, it will leave a very small opening, but you should be able to push it closed with your finger and then when you let off it should open up just a bit. Its usually not a bad idea to also remove the throttle plate from the cross bar and then polish the inside of the cylinder, making sure its smooth. There are two Torx bolts holding it in place and once you remove them it will only slide out in one direction due to there being two small bumps on the plate that wont fit through the bar. Before taking it out just note how its positioned in there and put it back the same way. I even use some very good gun oil called Zero Friction which has nano fluoro-polymers in it and I put a drop or two at the friction points where the cross bar goes into the walls of the throttle body and then work the plate open and closed a few times. This last time I did it, on a car I just bought, I removed the throttle plate and sprayed just around the outside diameter with a Kimball Midwest product called Graf-Coat which is dry graphite lubricant that goes on just like black spray paint. The aluminum throttle plates aren't the smoothest around the outside edge, It doesn't appear to me that Bosch polishes them, so when the TB's start to gunk up, the gunk sticks to the outside of those plates fairly easily; the graphite coating should help with that problem too.

    But what you describe is very very common symptons for a fouled up TB, and the fact that it got better after you did it the first time tells you something too.

    But if you are running an after market air filter that is oiled, it could be over oiled and dirtying up the MAF and the TB. Buy some electronic contact cleaner from Radio Shack and spray the hell out of the MAF. MAF's usually don't just go bad, there's usually a 3rd party acting on them to dirty them up which can make them fail. However, there are rare cases when the transducer lead can break inside the housing and then its for sure a gonner. I think you can see if its good or bad via Durametric... If memory seves me the MAF should read out voltage. In Durametric go into the DME and go to "see actual values" click on the MAF. With key on but not running the voltage should read .9 to 1.1 with engine running at idle it should be 1.2 to 1.5 and it should increase linearly when you apply more gas. You can also check this manually but its a little more difficult and you need a voltage meter. You keep the MAF plugged in and you need to put your voltage meter probes on pin 2 and 4 (should be labeled) on the MAF plug which you get to by pulling the rubber cover back away from the plug...

    Just my personal opinion here... But if you are running an aftermarket air filter like a K & N, the real life gains (not what they claim) aren't advantageous enough in my opinion to offset the superior flitering ability of the OEM paper air filters. I ran an OEM paper filter on my K24/18G car with less problems and no noticeable difference in power. Id rather have superior filtering than a few additional HP's.

    Hope you get the problem resolved, no fun having quirks.

    • Upvote 1
  13. GT1 motor = awesome. (except for glued in coolant bungs)

    M96 & M97 = 2.7

    9A1 = yet to be seen.

    I sold my 996TT X50 and bought a 997 Carrera S.... and now I'm debating my decision. The more research I do on these 3.8 M97 motors the more I get freaked out. They're just like the old 2.7 liter engines. Porsche bored out the 2.4 liter motors to make the 2.7 and in doing so the coolant passages got smaller and the motors were prone to overheat and failure... The 3.6 and 3.8 M97 motors are the exact same... larger displacement in same block as 3.4 and now they have coolant issues and are prone to cylinder scars and cylinder liner failures on bank 2. It sucks having a Porsche that you don't feel like you can ring it out without having a potential failure. I'm adding a radiator and changing the thermostat to a cooler unit and running a Tungsten Disulphide Fullerene Nano Particle additive to try and mitigate this problem from happening to me, but if I knew then what I know now I don't think I would have bought a 997.

    In my opinion the only Porsche 911's that are worth a **** now days are the Turbo's up to 2010 and all the GT cars. The rest I think have subtle engine design flaws that will lead to eventual failures at some point unless the owners are just very anal about keeping them as cool as possible and not following the Porsche recomended super stupid long maintenance intervals.

    You 996TT boys...stick with them. Those motors are awesome. Like the gentleman above, you may end up replacing everything around the motor, but motor failures are very very rare.

    I've only had my 997 for about a month and I'm debating selling it already. Love the car and the way it looks and handles but I'm paranoid about the motor now, which makes for a not fun owning experience. Porsche claims this great reliabilty but personally I think it's bunk. I bet if you do a per mileage failure rate the Porsche looks like crap compared to everything else. When you look at the failure rate per year they probably look pretty good as the majority of owners will have maybe 30K miles on a 6 year old car. I would hope in 30,000 miles of use there wouldn't be any major failures but even that's not the case... I know of guys with 20K mile M97 cars with cylinder liner failures. That's garbage! Luckily for one owner I know of, his failed outside of the CPO warranty and Porsche still agreed to pay for 85% of the repair so that's cool but I doubt that happens for the majority of people. The IMS issues and now the cylinder liner issues are both due to Porsche trying to save a buck in production. A car company that has the highest per car profit margin shouldn't be cutting corners on engine design.

  14. Remve the throttle body and clean the hell out of it...probably gunked up. Then when you put it back on, turn the ignition on but dont start the car and go back by the engine bay and wait for about a minute untill you hear a whine and few clicks and then when the sound stops turn the car off. Then start the car and let it idle for around 10 minutes or so. This resets the throttle body and idle control...

  15. Fyi...the only true full synthetic Mobil 1 is the European type. Mobil 1 lost a law suit awhile back against Castrol that claimed their oil was full synthetic when it was actually a blend. So Mobil jumped on the bandwagon... Figured why spend the big bucks on producing a true full synthetic if they can claim full synthetic with a blend. But due to the OEM Euro oil requirements, they still have to produce a true real full synthetic oil so thats the European that you see sold (walmart) has it.

    But if you want to run the best full on latest tech full synth oil...buy Royal Purple XPR. do some research and you'll find oil tests out there and that was the best of the best.

    Also...if you drive your TT often, it wont smoke. And cool it off before shutting it down.

    Mine burns very little, maybe half quart every 1500 miles or so..and its mod'd.

  16. Almost forgot...

    As far as ECU tuning...

    Avoid Softronic... (my humle opinion)

    I had a Softronic tune on the oem turbos and it was fine.

    After the k24/18g upgrade i had to pay Softronic for another map...

    That map was way too rich (cold smell fuel out the exhaust constantly)

    Tried to contat Softronic a few times to remedy the problem and I always felt like I was annoying them or getting in the way. I guess they only have 1 person over there that does the tunes? A few times I contacted them, that ONE guy was on vacation in Europe and I would have to wait.... Huh? Really?

    So I cut my losses and ditched their sub-par program and shelled out more coin for one of MarkSki's tunes at 911Tuning.com.

    I must say, Mark is the man! He's the Yin to Softronics Yang... He was polar opposite from them, always available to help, even on 4th of July holiday weekend he was answering my questions and helping me out.

    Their map is perfect too. Afrs are in the sweet spot and the timing is perfect.

    Their customer service is 2nd to none...highly recommended!

  17. Update: ( just in case someone else gets this problem)

    Reason for the P1508 Torque Comparison code after installing K24/18g hybrids..

    Massive boost leak on one of the intake air runners leading directly into the motor. In my case it was the first cylinder, closest to the front of car on the psgr side...not easy to get to.

    Had to replace the small rubber hose and the worm clamp, and had the shop strap the intake runners down just for a secondary precaution.

    No problems since...

    But on a 2nd note... If anyone is interested in the K24/18 swap, dont go the 5 Bar FPR route. Im not sure whom came up with this but the 5 bar FPR can't keep up with the fueling needs.

    I was maxing at 1.2 bar of boost and my injector duty cycle was 100 to 125% with the 5 bar installed.

    So i went back to the 3.8 bar FPR and had larger injectors installed and now at 1.3 bar boost my injector duty cycle is 75%

    Hope this helps someone...

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.